xref: /openbsd-src/usr.bin/env/env.c (revision dd24756f1f8299c5d226ef2fe14ef8cdd81f2da7)
1 /*	$OpenBSD: env.c,v 1.19 2024/07/28 21:44:42 kn Exp $	*/
2 
3 /*
4  * Copyright (c) 1988, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <err.h>
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 
39 static void __dead usage(void);
40 
41 int
42 main(int argc, char *argv[])
43 {
44 	extern char **environ;
45 	extern int optind;
46 	char **ep, *p;
47 	int ch;
48 
49 	if (pledge("stdio exec", NULL) == -1)
50 		err(1, "pledge");
51 
52 	while ((ch = getopt(argc, argv, "iu:-")) != -1)
53 		switch(ch) {
54 		case '-':			/* obsolete */
55 		case 'i':
56 			if ((environ = calloc(1, sizeof(char *))) == NULL)
57 				err(126, "calloc");
58 			break;
59 		case 'u':
60 			if (unsetenv(optarg) == -1)
61 				err(126, "unsetenv");
62 			break;
63 		default:
64 			usage();
65 		}
66 	argc -= optind;
67 	argv += optind;
68 
69 	for (; *argv && (p = strchr(*argv, '=')); ++argv) {
70 		*p++ = '\0';
71 		if (setenv(*argv, p, 1) == -1) {
72 			/* reuse 126, it matches the problem most */
73 			err(126, "setenv");
74 		}
75 	}
76 
77 	if (*argv) {
78 		/*
79 		 * return 127 if the command to be run could not be
80 		 * found; 126 if the command was found but could
81 		 * not be invoked
82 		 */
83 		execvp(*argv, argv);
84 		err((errno == ENOENT) ? 127 : 126, "%s", *argv);
85 	}
86 
87 	for (ep = environ; *ep; ep++)
88 		(void)printf("%s\n", *ep);
89 
90 	return 0;
91 }
92 
93 static void __dead
94 usage(void)
95 {
96 	extern char *__progname;
97 
98 	(void)fprintf(stderr, "usage: %s [-i] [-u name] [name=value ...] "
99 	    "[utility [argument ...]]\n", __progname);
100 	exit(1);
101 }
102